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Open data
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Basic information
| Entry | Database: PDB / ID: 9q06 | |||||||||||||||||||||||||||
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| Title | Symmetric Inactivated Locked State | |||||||||||||||||||||||||||
Components | Ferredoxin--NADP reductase | |||||||||||||||||||||||||||
Keywords | OXIDOREDUCTASE / HEM / FAD / NOS / FMN / C2 domain | |||||||||||||||||||||||||||
| Function / homology | FLAVIN-ADENINE DINUCLEOTIDE / FLAVIN MONONUCLEOTIDE / PROTOPORPHYRIN IX CONTAINING FE / : Function and homology information | |||||||||||||||||||||||||||
| Biological species | Synechococcus sp. PCC 7335 (bacteria) | |||||||||||||||||||||||||||
| Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.9 Å | |||||||||||||||||||||||||||
Authors | Nair, D. / Xu, Y. / Crane, B. | |||||||||||||||||||||||||||
| Funding support | United States, 1items
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Citation | Journal: Sci Adv / Year: 2026Title: Structure and dynamics of a multidomain nitric oxide synthase regulated by a C2 domain. Authors: Dhruva Nair / Brian R Crane / ![]() Abstract: Nitric oxide synthase (NOS) is a widely studied multidomain redox enzyme that produces the key signaling molecule and cytotoxic agent nitric oxide (NO) for functions that range from mammalian ...Nitric oxide synthase (NOS) is a widely studied multidomain redox enzyme that produces the key signaling molecule and cytotoxic agent nitric oxide (NO) for functions that range from mammalian vasodilation to prokaryotic antibiotic resistance. NOS enzymes from metazoans and cyanobacteria rely on dynamic associations of their oxygenase and coupled diflavin reductase domains that have largely evaded detailed structural characterization. Cryo-electron microscopy studies of a representative dimeric six-domain NOS reveal the architecture of the full-length enzyme, which contains an unusual regulatory C2 domain, and additional nitric oxide dioxygenase (NOD) and pseudoglobin modules. Five distinct structural states depict how pterin binding couples to tight and loose oxygenase conformations and how the Ca-sensitive C2 domain moves over 85 angstroms to alternatively regulate either the NOS or NOD heme center. The extended carboxyl-terminal tail and its dynamic interactions highlight an added layer of regulation required by multidomain NOSs compared to other diflavin reductases. | |||||||||||||||||||||||||||
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Structure visualization
| Structure viewer | Molecule: Molmil Jmol/JSmol |
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Downloads & links
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Download
| PDBx/mmCIF format | 9q06.cif.gz | 931 KB | Display | PDBx/mmCIF format |
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| PDB format | pdb9q06.ent.gz | 775.3 KB | Display | PDB format |
| PDBx/mmJSON format | 9q06.json.gz | Tree view | PDBx/mmJSON format | |
| Others | Other downloads |
-Validation report
| Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/q0/9q06 ftp://data.pdbj.org/pub/pdb/validation_reports/q0/9q06 | HTTPS FTP |
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-Related structure data
| Related structure data | ![]() 72088MC ![]() 9q05C ![]() 9q0xC ![]() 9q0yC ![]() 9q15C M: map data used to model this data C: citing same article ( |
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| Similar structure data | Similarity search - Function & homology F&H Search |
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Links
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Assembly
| Deposited unit | ![]()
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Components
| #1: Protein | Mass: 166440.266 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Synechococcus sp. PCC 7335 (bacteria) / Gene: S7335_573 / Production host: ![]() References: UniProt: B4WU43, nitric oxide dioxygenase, assimilatory sulfite reductase (NADPH) #2: Chemical | ChemComp-HEM / #3: Chemical | #4: Chemical | Has ligand of interest | Y | Has protein modification | Y | |
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-Experimental details
-Experiment
| Experiment | Method: ELECTRON MICROSCOPY |
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| EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
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Sample preparation
| Component | Name: Symmetric Inactive / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT |
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| Molecular weight | Value: 0.320 MDa / Experimental value: NO |
| Source (natural) | Organism: Synechococcus sp. PCC 7335 (bacteria) |
| Source (recombinant) | Organism: ![]() |
| Buffer solution | pH: 7.5 |
| Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
| Specimen support | Grid material: COPPER |
| Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE |
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Electron microscopy imaging
| Experimental equipment | ![]() Model: Talos Arctica / Image courtesy: FEI Company |
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| Microscopy | Model: FEI TECNAI ARCTICA |
| Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 200 kV / Illumination mode: OTHER |
| Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 2000 nm / Nominal defocus min: 500 nm |
| Image recording | Electron dose: 50 e/Å2 / Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) |
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Processing
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| CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||
| Symmetry | Point symmetry: C2 (2 fold cyclic) | ||||||||||||||||
| 3D reconstruction | Resolution: 3.9 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 133978 / Symmetry type: POINT | ||||||||||||||||
| Refinement | Highest resolution: 3.9 Å Stereochemistry target values: REAL-SPACE (WEIGHTED MAP SUM AT ATOM CENTERS) |
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Synechococcus sp. PCC 7335 (bacteria)
United States, 1items
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FIELD EMISSION GUN